Driving means for rotary knives of paper machines



April 12, 1932. D. R. FRANCIS V Y 5 I DRIVING MEANS FOR ROTARY KNIVES OFPAPER MACHINES Filed, Dec. 27, 1928 12 Sheets- Sheet 11 INVENTOR.DAN/EL. R. FBA/vc/s H I I. ATTORNEY April 12, 1932. D, R, FRAN E1,853,267

DRIVING MEANS FOR ROTARY KNIVES OF PAPER MAQHINES Filed Dec. 27, 1928 2Sheets-Sheet 2 MMTORNE are required by the specifications.

Patented Apr. 12, 1932 1 UNITED sures PATENT OFFICE DANIELE. 0FWATEBBUBY, EEO THE WATERBUQY TOOL COMPANY, DIE WATERIBURY,CONZNEGTIGUEiA CORPORATION OF CONNECTICUT nnrvnre mans :eon norenr orzenrnnmacnmns lpgplication filed December 27,; 1928. Serial No. 328,785.

' various lengths according to the specifications or demands of thepurchaser. It has not been found practical in the past to cut the paperweb as it leaves the paper machine into sheets of the desired lengthwith sufficient accuracy and therefore it has been the practice to setthe rotary paper knife, rovided at the end of the paper machine, so t atthe sheets cut by such knife will be sufliciently longer than the properlength to afford the necessary material for trimming the paper in apaper cutting mathe structure shown in Fig. 1 and Fig. 3 is chine intosheets of the requlred length. Becauseof the fact that the speed of thepaper machine is'varied for different weights of paper, or differentgrades of stock, it becomes necessary to vary the adjustment of therotary paper knife of the paper machine from time to time even when aconstant length of cut sheet is desired. A variation of the speed of therotary paper cutter is also necessary whenever sheets of differentlengths Various forms of change'speed drives have been employed in thepast for permitting the speed of the rotary paper cutter to be adjusted.Variable speed motors, cone pulleys and the like have heretofore beencommonly employed for driving the paper knife. Such drives as haveheretofore been used have iven considerable diiiic'ulty because of theact that it was impossible to adjust them to secure accurate and uniformcutting of the paper web into sheets of the proper length. It wastherefore the practice, in order to avoid cutting the sheets too short,to adjust the rotary knife so that it would cut the web into sheetsquite a considerable amount longer than necessary for providing therequired margin for the final trimming of the paper. As will be readilyunderstood the excess trimming margin left ,on the sheets for the finaltrlmming operation constitutes waste and this waste in the past hasamounted to :a

considerable percentage of the whole produc tion. It is the object ofthe present invention 1 to provide-a new and improved drive for therotary paper knife of the paper machine by means of which the relativespeed of such knife to the linear speed of the paper web can beproportioned with great accuracy and uniformity of operation. I

The above and other objects will appear more fully from thefollowing'more detailed description and by reference to the accompanyingdrawings forming a part hereof and wherein Fig. 1 is a plan view of adelivery end of'a paper machine showing the installation andapplication, constructed in' accordance with the principles of thisinvention, of a drive for the rotary knife of the paper machine; Fig. 2is a side elevation of ed to it, by means of a flexible coupling 12,

the driving shaft of a hydraulic motor 13. Fluid under pressure from ahydraulic pump 14 is supplied to the motor 13 through the pipes 15 and16.

The hydraulic pump 14. is driven from any of. the rotating members orshafts of the paper machine whose speed of rotation is proportional tothe linear speed of the paper web delivered by the machine. In theparticular constructional example disclosed the pump 14: has its drivinshaft connected, by means of a flexible coup g, to a shaft extension 17the latter being supportedin bearings 18, 19 supported upon any suitablefoundation, such as the base plate 20. Located between the bearings 18and 19 and keyed to the shaft extension 17 is a chain gear the drivingshaft. Each cylinder has mounting by means 26 varied as desired.

ed for reciprocation therein a piston 28. The pistons 28 are connectedby piston rods 29 with a swash plate 30 mounted for rotation within atilting box 31. In accordance with the usual construction'of theWaterbury type gearing, the tilting box of the motor 13, or B-end, as itis usually called, is held at a fixed inclination to the driving shaft26, while the tilting box of the pump, or A-end, 14 may have its angleto the driving shaft Means are provided for adjusting the tilting boxand swash plate of the. motor and such means consist of a control shaft32, which, in the articular constructional example disclose is providedwith a screwthreaded portion which on ages the screwthreads ofarotatable nut 33. hen the motor, swash plate and tilting box are set bythe control shaft to extend atright angles to the driving shaft 26, thepistons 28 will have no stroke and no fluid will be deliveredby thepump. This is called the neutral position of the gear. When thetiltboxand swash plate are inclined in either direction from the neutralposition, fluid will be pumped in one or the other direction through thepipes 15 and 16, and the amount of fluid so pumped, orthe output, willincrease proportionately to the extent of the inclination given to theswash plate and tilting box. 4 I

n the particular constructional example herein disclosed, the adjustmentof the control shaft 32 is effected by means of a manually operable handwheel 35, preferably se cured upon a hand wheel shaft 36, mounted forrotation in bearings 37 upon the side of the supporting bracket orstandard 38 in which the ends ofthe shaft of the paper cut-' ting knifearev journaled. Secured to the hand wheel shaft 36 is a sprocket gear 39about which and a similar sprocket 40 is trained a sprocket chain 40".The sprocket 40 is mounted upon one end of a shaft 41 extendinglongitudinally of, and suitably supported upon, the side frame of thepaper machine. The shaft 41 is connected by means of a second chain andsprocket connection 42 with one end of a second longitudinal shaft 43.The other end of the shaft 43 extends into a gear reduction box 44 whichbox is provided with suitable reduction gearof which the rotation of thea greater distance shaft 43 is communicated to a vertically extendingshaft 45 the upper end of which extends into the gear box 44 and thelower end of which is suitably connected to the control shaft nut 33.

The manner in which the installation operates is as follows: When thepaper machine is in operation the rotation of the shaft 23 of the drierdrive will be communicated throughthe chain drives'21, 22 to thedriving. shaft of the pump 14. The control shaft 32 of the pumpisadjusted by means of the hand wheel35 and the connecting gears andshafts 39 to 45 inclusive to bring about a delivery of fluid by the pumpfor producing a rotation of the hydraulic motor 13 and the rotary paperknife 11 at the desiredspeed relatively to the linear speed of deliveryof the pa er for cutting the web into sheets of desire length. As thehydraulic speed gear is capable of infinite speed variation the exactsetting of the control shaft is easily obtained for any desired lengthof sheet.

When the control shaft has once been set, the

drive of thepaper knife will be so accurate and positive that the mar 'nleft for trim is practically negligible. s the hydraulic drive operateswith a practically incompressible fluid, such as oil, no fluctuations orvariations in speed of-the gear can occur and consequently the paperknife will continue to operate uniformly at the proper speed. If thespeed of the paper machine is varied forv any reason whatsoever theratio of the speed of rotation of the aper knife to the linear speed ofdeliver 0 the paper will not be varied because of t e fact that the pumpof the hydraulic speed gear is driven directly by one of the rotatingparts of the paper machine.

In the particular constructional example disclosed, thev pump of thehydraulic gear has been located at a point quite distant from the motor13. This arrangement however is merely illustrative. Obviously the pumpmay be located'at any desirable point, for example, the pump or A-endmight be driven from the variable speed line of the paper machine, or iffor any cause it should be found desirable to locate the pump at evenfrom the motor than shown in the drawings, the latter could readily bedone because of the fact that the fluid circulated from the pump to themotor through the pipe lines 15, 16 and as such pipe lines may be bentin any desired direction and the length thereof is immaterial. It willbe understood that the constructional details of the gearing and shaftconnections between,

of these details as well as other minor details of the installationdisclosed may be resorted to without departing from the principles ofthe invention.

I claim:

1. In a machine for cutting a travellin web of material, driving meansfor saidwe of material, a rotary web cutting knife, and variable speedmeans for driving said knife, said variable speed means comprising afluid pressure pump, driving connections between said pump and saidfirst named drivingmeans whereby the speed of said pump isdetermined bythe speed of travel of said web, a fluid pressure motor, drivingconnections between said motor and knife, said pump having an adjustablecontrol shaft by means of which its rate of output may be variedinfinitely between predetermined limits, a manually operable adjustingdevice located immediately adjacent to said paper knife, gearingconnections between said adjusting device and said control shaft, andconnections between said pump and motor whereby the operative speed ofsaid knife bears a predetermined relation to the speed of travel of saidweb and is automatically maintained in said relation regardless ofvariations in said speed of travel of the web.

2. The combination with the rotary paper so cutting knife of a papercutting machine, of

means for automatically maintaining a precise, accurate adjustment ofthe speed of rotation of said knife relatively to the linear speed ofthe paper delivered by said machine whereby said knife will out saidpaper into sheets of uniform length irrespective of variations in theabsolute linear speed of said paper, said means comprising arotary fluidpressure pump, positive driving connections of invariable effect betweena rotating part of said paper machine and said ump, a rotary fluidpressure motor, positive driving connections between said motor and saidpaper knife, and conduits connecting said pump and motor, said pumpbeing provided with an adjustable control shaft for varyin its outputand thereby the speed of sai motor, a manually operable hand wheellocated adjacent tosaid rotary knife and gear.- ing connecting said handwheel and the control shaft of said pump, said gearing including areduction gear whereby a relatively large movement of said hand wheelwill produce a small extent of movement of said control shaft therebyenabling a fine adjustment of the output of said pump and a similaradjustment of the speed of rotation of said motor. and knife to besecured.

In testimony whereof I have hereunto set my hand.

' DANIEL R. FRANCIS.

